The present invention relates to an apparatus for inserting a small-diameter pipe into a large-diameter pipe and/or pulling the former out of the latter.
An apparatus has not been provided yet which is specifically designed for inserting a small-diameter pipe into a large-diameter pipe or withdrawing the former from the latter. Accordingly such work has been conducted by a very primitive method generally using the following device.
As illustrated in FIG. 8, if a small-diameter pipe 2 is to be inserted into a large-diameter pipe 1, for instance, an inverted U-shaped pivotable member 39 is engaged with the large-diameter pipe 1, and one end of a wire 40 wound around the small-diameter pipe 2 is fixed to the pivotable member 39. The pivotable member 39 is then pivotally moved by the hands in the direction of the arrow in the drawing to insert the small-diameter pipe 2 into the large-diameter pipe 1.
However, the conventional device requires a troublesome procedure to wind the wire 40 around the small-diameter pipe 2 and to remove the wire 40 from the pipe 2 after the completion of work and involves another drawback that pivotable members of various sizes must be prepared in accordance with the diameters of the pipes to be handled. Furthermore when the small-diameter pipe 2 is to be inserted in place, the pull on the wire 40 brings the small-diameter pipe 2 out of alignment with the large-diameter pipe 1, making it impossible to insert the small pipe 2 into the end of the large pipe 1 while maintaining both pipes 1 and 2 in alignment with each other. With the known device, therefore, it is difficult to carry out the work smoothly, or the small-diameter pipe 2 is inserted into the large-diameter pipe 1 out of alignment therewith.